We recently bought a house that had an addition put on in the 80's. The addition is on the back of the house and has separate (electric) heating and cooling. In the ceiling are two square, 12.75" air diffusers. Picture here:

enter image description here

The hole that it covers measures 12.75", but the actual cover seen here measures 17.5". The other thing is that I'm having a hard time finding different ones in this size.

Personally, I've never seen these used in residential, only commercial. And frankly, they're ugly. They're the first things you notice when you walk into the room. Is there an alternative that is more updated and more attractive that I'm not aware of? I would settle for the same thing, but one that doesn't drop down 3" or so from the ceiling (the more flush the better).

  • 1
    If you look inside, how big is the pipe that is supplying this vent? Typically, most rooms get somewhere between a 4 and 6" round duct, depending on the size of the room and distance (and probably some other factors -- I'm not an HVAC expert). If this is in fact just a 6" (or smaller) pipe, then you can definitely get away with putting in a 6" round diffuser, and patching up the drywall to make the hole smaller.
    – gregmac
    Oct 24, 2011 at 1:01
  • 1
    @gregmac The pipe supplying the vent is a square, hard metal air duct that is 12.75" x 12.75", so anything smaller would not work.
    – Matt
    Oct 24, 2011 at 1:43

1 Answer 1


As long as the cover is the same size as the opening (or otherwise impede air flow), you can probably use any cover.

I would start by searching for ceiling vent or grilles.

12x12 inches is a common size for vents, so there should be many options available depending upon your budget.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.